Modern tactical aircraft use a number of imaging aids to assist the crew in viewing a scene, selecting targets in the scene, and directing weapons against the selected targets. Visible, infrared, and/or specific spectral bands imaging devices are used in various applications to form an image of the scene. The type imaging spectrum depends upon the mission, weather conditions, the nature of the scene, as well as other factors.
The field of view of an imaging device, used to form the image of the scene, describes the range of the captured scene. A wide field of view allows the imaging device to capture a large area of the scene. In turn, a smaller field of view captures less of the scene, allowing the image device to “focus in” on the image, and may further help to discern small features within the image.
Multi-spectral targeting systems may use both infrared and visible light imaging sensors and may include multiple different optical systems suited for use with each type of sensor. For example, optical system used with an infrared image sensor may not be suitable for use with a visible light image sensor. Additional optical systems may be included in the multi-spectral targeting systems for capturing images with different fields of view. There is a need to enable several detectors to share a common aperture in combinations of two or more detectors. Presently, a stationary prism assembly divides light into up to three directions for the illumination of detectors. However, presently available switching mirrors allow light to pass to only one of three possible detectors.